Bosch super sound box is full range of passive speakers, suitable for all kinds of needs large power output, wide controlled diffusion Angle, and the application of wide frequency occasions, can install spirit live indoors and weatherproof outdoor places. Bosch series large super sound speakers come in two sizes. 12 inches and 15 inches. All models adopt two - frequency loudspeaker and ABS VO shell. The 1-inch compression actuator unit of this series of speakers is coupled with an impedance transformer, with constant directionality, and is equipped with a direct radiation type 12-inch or 15-inch speaker. Typical applications include an auditorium, an assembly hall, a community center, a cinema, an assembly hall, a factory, a multipurpose hall, and a gymnasium. Self-recovery protection device can prevent high frequency excitation unit from being damaged due to accidental overload. The transformer can receive 100 V or 70 V, 40 hz-22 kHz signal number. System overview lb3-pc250 comes with a 12-inch bass unit and a 1-inch sound compression drive unit. The lb3-pc350 is equipped with a 15-inch bass unit and a 1-inch sound compression drive unit. The super sound box USES a specially designed horn that provides a constant sound coverage regardless of the frequency. The handle and hang decoration are located in a specific position to facilitate the removal of the speaker and the alignment of the speaker during installation. The bottom of the speaker box is integrated with a pole mounting base and provides a weatherproof steel mesh cover. All screws and bolts are stainless steel or rust-resistant. Speakers are specially designed to be mounted near side walls or on the floor. Good moisture - proof, collision - resistant and weatherproof (roofed). 5 ‑ PC250 and 5 ‑ PC350 suitable for installed in high pressure, wide bandwidth audio and no ac power or don't want to install active speakers, such as room outside applications or applications can play 100 V technological edge, and can be easily connect a speaker cable is quite long). Lb3-pc250 and lb3-pc350 have 100/70v transformers with power taps. Loudspeaker weatherproof (IP44, can be installed in the protected outdoor field). The basic function speaker has two SPEAKON connectors connected in parallel. SPEAKON's input terminal is below the waterproof cover on the back of the speaker box. A waterproof splash cover is installed above the control part of the backboard to prevent moisture, pollution and damage. Under the hood, the input terminal of SPEAKON can be found, and you can choose to connect channel 1 or channel 2 to the ceramic junction box. Alternatively, you can connect the E30 wire directly to the ceramic junction box (with thermistor) through the PG11 waterproof sealing sleeve. The speaker box has two PG11 positions to connect the loop of the wire. Choose the speaker tap from the ceramic junction box. Full power, half power and one quarter power are available at 100 V and 70 V voltages. Fender have a dedicated to install EOL (line terminal) the location of the LED lamp, if you use Bosch EOL circuit board, can also be installed in this position, the dedicated line monitoring equipment, to monitor individual speakers or lines. The speaker box has a special notch filter built in to filter out 20 kHz pilot tones. This reduces the 20 kHz lead tone. The filter can pass by the bridge (standard parts) bypass. Security components including thermal fuse, pottery and porcelain in the junction box of transformer thermal fuse (evacuation standard) and high frequency filter output and the high frequency excitation single yuan between automatic reset type current limiting circuit.